How the time calculator works
Add & subtract mode works like a list of durations. Each row has a plus or minus sign (the first row is always added) and fields for hours, minutes and seconds. Hours can go up to 99,999, and you can use up to 30 rows. Empty fields count as zero.
The total is shown as hours:minutes (with seconds when there are any), in words, in decimal hours, as total minutes, as total seconds and in days and hours. If you subtract more than you add, the result is shown as a negative duration.
Time between two times takes a start and an end clock time in 24-hour format and returns the elapsed time. An end time earlier than the start time is treated as the next day, which is what you want for a night shift or a late flight.
Examples
| Calculation | Result | Other formats |
|---|---|---|
| 1:45 + 2:30 | 4:15 | 4.25 h, 255 min, 15,300 s |
| 2:35 + 1:50 + 3:15 | 7:40 | 7.6667 h, 460 min |
| 20:00 + 5:00 | 25:00 | 1 day 1 hour |
| 8:00 − 0:45 | 7:15 | 7.25 h, 435 min |
| From 08:45 to 17:20 | 8:35 | 8.5833 h |
| From 22:00 to 06:00 | 8:00 | crosses midnight |
How the first line works: 45 + 30 = 75 minutes, which is 1 hour 15 minutes, so 1 + 2 + 1 = 4 hours and 15 minutes. In decimal, 15 ÷ 60 = 0.25, giving 4.25 hours.
For the 08:45 to 17:20 example, 08:45 to 16:45 is 8 hours and 16:45 to 17:20 is 35 more minutes. 35 ÷ 60 ≈ 0.5833, so 8.5833 hours.
Common uses
- Using it as a time adder for the time spent on tasks, lessons or video clips.
- Totalling hours and minutes for a timesheet, then converting them to decimal hours for payroll.
- Finding the duration of a shift, a journey or a sleep period between two clock times.
- Subtracting a break or a pause from a total duration.
Good to know
- Durations are pure arithmetic on hours, minutes and seconds, so daylight-saving changes never affect the result. If a period really does include a clock change, the actual elapsed time will be one hour more or less.
- Minutes and seconds accept values from 0 to 59; enter 90 minutes as 1:30.
- For a work shift with an unpaid break, the work hours calculator subtracts the break and can split out overtime. For a whole week, fill in a weekly time card.
- To count calendar days rather than hours, count the days between two dates.